<!DOCTYPE HTML>
<html><head>

<style>
#s {
  position: absolute;
  top: 20px;
  left: 20px;
  display: block;
  width: 400px;
  height: 150px;
  box-shadow: 0px 250px black;
}
</style>

</head>
<body>

<input type="file" id="s" />

</body>
</html>
